A display device such as a smartphone includes a mobile phone function and a data communication function. That is, a user may install or delete various applications in a display device as desired. In addition, a user may perform communication with other people using a telephone, a message or a social network service (SNS) using a display device.
A user may easily place a phone call or send a text message to a desired counterpart using a display device. At this time, the user may wonder whether the counterpart is currently in a contactable state in addition to making a phone call or sending a text message to the counterpart. That is, there is a need for a method of immediately and easily checking a contactable state of a counterpart in addition to a phone call or a text message.